feat(web/attackers): surface ASN + AS name on cards and detail

Attacker list cards gain an AS<number> chip with the AS description
on hover. Attacker detail page adds an AS row beside ORIGIN — same
shape as the existing country/source pair so operators can read
"this attacker is in DE on AS24940 Hetzner" at a glance instead of
having to grep the IP into a separate tool.

Both fields collapse to "unknown" when the IP isn't BGP-announced
(CGNAT, dark space, RFC1918), matching the existing pattern for
country resolution.

decnet_web/src/components/AttackerDetail.tsx

@@ -61,6 +61,9 @@ interface AttackerData {
   commands: { service: string; decky: string; command: string; timestamp: string }[];
   country_code: string | null;
   country_source: string | null;
+  asn: number | null;
+  as_name: string | null;
+  asn_source: string | null;
   ptr_record: string | null;
   updated_at: string;
   behavior: AttackerBehavior | null;
@@ -1262,6 +1265,26 @@ const AttackerDetail: React.FC = () => {
               <span className="dim">unknown</span>
             )}
           </div>
+          <div>
+            <span className="dim">AS: </span>
+            {attacker.asn != null ? (
+              <span className="matrix-text">
+                AS{attacker.asn}
+                {attacker.as_name && (
+                  <span className="dim" style={{ marginLeft: 6, fontSize: '0.75rem' }}>
+                    {attacker.as_name}
+                  </span>
+                )}
+                {attacker.asn_source && (
+                  <span className="dim" style={{ marginLeft: 6, fontSize: '0.75rem' }}>
+                    ({attacker.asn_source})
+                  </span>
+                )}
+              </span>
+            ) : (
+              <span className="dim">unknown</span>
+            )}
+          </div>
           <div>
             <span className="dim">REVERSE DNS: </span>
             {attacker.ptr_record ? (

decnet_web/src/components/Attackers.css

@@ -92,6 +92,16 @@
   font-size: 0.72rem;
   opacity: 0.7;
 }
+.attackers-root .ak-card .ak-asn {
+  font-size: 0.62rem;
+  letter-spacing: 1px;
+  padding: 1px 6px;
+  border: 1px solid var(--border);
+  color: var(--matrix);
+  opacity: 0.75;
+  font-weight: 600;
+  cursor: help;
+}
 
 .attackers-root .ak-stats {
   display: flex;

decnet_web/src/components/Attackers.tsx

@@ -25,6 +25,9 @@ interface AttackerEntry {
   commands: any[];
   country_code: string | null;
   country_source: string | null;
+  asn: number | null;
+  as_name: string | null;
+  asn_source: string | null;
   updated_at: string;
 }
 
@@ -209,6 +212,14 @@ const Attackers: React.FC = () => {
                   <div className="ak-meta">
                     <span>First: {new Date(a.first_seen).toLocaleDateString()}</span>
                     <span>Last: {timeAgo(a.last_seen)}</span>
+                    {a.asn != null && (
+                      <span
+                        className="ak-asn"
+                        title={a.as_name ? `${a.as_name}${a.asn_source ? ` (${a.asn_source})` : ''}` : undefined}
+                      >
+                        AS{a.asn}
+                      </span>
+                    )}
                     {a.is_traversal && <span className="chip violet" style={{ fontSize: '0.6rem' }}>TRAVERSAL</span>}
                   </div>